'Mr. Shanks, Lund and Sons' superintendent engineer, stated that the coal consumption of the Waratah was 15 tons per day more on the second voyage, due to the distillation of drinking water and weather conditions.'
This is a very interesting statement and explanation.
Immediately a question is raised regarding the distillation of drinking water. Why would it be any different from the first voyage? In fact, there were about 700 emigrants (full capacity) on the first outbound voyage which surely placed maximum demand on water distillation. The comment about the weather could be true to some extent. The maiden voyage took place during the Southern Hemisphere summer months - reduced incidence of rough sea conditions off South Africa and in the southern Indian Ocean. But would this equate to an extra 15 tons per day?
There is a further possible explanation; in order to improve the Waratah's metacentric stability after the teething problems encountered on the maiden voyage, I believe that the Waratah was significantly heavier in terms of dead weight. This could have accounted for the increased coal consumption taking into consideration Waratah's relatively under powered engines.
Lastly Waratah made all her passages a day or so ahead of shcedule - this was not specific to her final voyage when she made Durban a day ahead of schedule.